Environmental Engineering Reference
In-Depth Information
analyses defi ning time limits of safe operation (time-limited ageing anal-
yses (TLAAs)) and corresponding monitoring of time limiting assump-
tions (e.g. fatigue monitoring)
ageing management programmes (AMPs)
environmental
qualifi cation and programmes for maintaining the
qualifi cation
maintenance and control of effectiveness of maintenance with respect
to safety criteria
scheduled replacements and reconstructions.
This system should be comprehensive in the sense that ageing of any item
in the list of safety-related SSCs, should be covered by at least one of the
methods. The required safety function and performance of any selected SSC
has to be ensured by one of the approaches listed above or a combination
of the methods/programmes (e.g. AMP and TLAA). The safety functions
are properly ensured if the non-safety classifi ed items, which may affect the
safety functions, are also covered by one of the programmes.
The operator should pay specifi c attention to those structures and com-
ponents, the function and performance of which directly limit plant life-
time. These are the non-replaceable or not-to-replace SCs to which either
an effective ageing management programme should be applied, or the
required functions should be demonstrated for the extended operational
time by analysis (fatigue, embrittlement, etc.) or by qualifi cation (e.g. in case
of cables).
There are different approaches to how the operator defi nes which method/
programme or combination thereof is applicable for particular SSCs; the
optimization of plant efforts may have economical aspects too. The exist-
ing plant programmes might be credited as appropriate for ensuring the
required plant condition in the long-term, if they are reviewed and found to
be adequate. The concept outlined above is illustrated in Table 8.3.
8.4.1 Ageing management strategies and ageing
management programmes
Scope of ageing management
The scope of the review covers the following SSCs:
SCs relevant for safety - Classes 1, 2 and 3
those non-safety SCs which can jeopardize the safety functions.
The non-safety-related SSCs which can jeopardize the environment (oil
pipelines and tanks, containers for storing different chemical substances)
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